1. Technical Field
The present disclosure relates to a network device.
2. Description of the Related Art
Currently, High-Definition Multimedia Interface version 1.4 (HDMI 1.4) supports an Ethernet transmission, such that traditional Ethernet's wiring can be replaced by HDMI's cable.
However, system vendors such as DVD providers cannot ensure whether the clients support HDMI 1.4 and Ethernet transmission or not at the initial stage. For this reason, the system vendors certainly will reserve both the traditional Ethernet connector and the HDMI connector with Ethernet functions in hardware, and thus two groups of media access control layer circuits (MAC circuits) and physical layer circuits (PHY circuits) are required.
For example, one group of MAC circuit and PHY circuit is connected to an asymmetric digital subscriber line (ADSL) via the RJ-35 network connection, while another group of MAC circuit and PHY circuit is connected to the TV via HDMI and then connected to the ADSL via the TV. In doing so, a loop may be formed in the network so as to cause frame circulation and frame propagation in the loop, or even cause broadcast storm occupying lots of network bandwidth. A way of solving the problem resulted from the network loop is to adopt a spanning tree protocol (STP). However, by adopting the spanning tree protocol, it usually results in disadvantages of occupying a lot of resources of the processor and memories.
Hence, how to avoid the problem caused by the network loop itself has become an important issue to be solved by designers in this field.